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Finding the Fourth Proportional to 83.69, 115.43 and 72.75

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Solution

The fourth proportional to 83.69, 115.43 and 72.75 is: 100.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.69 : 115.43 = 72.75 : x
  2. Step 2: Convert to fraction form
    83.69/115.43 = 72.75/x
  3. Step 3: Cross multiply
    83.69x = 115.43 × 72.75
  4. Step 4: Simplify right side
    83.69x = 8,397.17
  5. Step 5: Solve for x
    x = 8,397.17/83.69
  6. Step 6: Final answer
    x = 100.34

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.